Commitments and Contingencies (Loss Contingency) (Details) (USD $) In Millions, unless otherwise specified		12 Months Ended		1 Months Ended		3 Months Ended	12 Months Ended
	Jun. 30, 2012 action	Dec. 31, 2009 State of Nevada Department of Taxation Sales and Use Tax Deficiency	Jun. 30, 2012 State of Nevada Department of Taxation Sales and Use Tax Deficiency	Feb. 28, 2009 County Assessor Property Tax Assessment	Dec. 31, 2007 County Assessor Property Tax Assessment	Mar. 31, 2012 County Assessor Property Tax Assessment	Dec. 31, 2011 County Assessor Property Tax Assessment	Jun. 30, 2012 County Assessor Property Tax Assessment
Loss Contingencies [Line Items]
Number of legal actions brought against company to date	2
Amount of assessment by taxing authority		$ 12.3			$ 6.2
Amount of increase (decrease) of initial tax assessment by taxing authority				(2.2)
Amount of interest assessed by taxing authority		7.5
Increase in assessed property value, percentage					400.00%
Property tax settlement, reduction in property tax accrual							9.7
Property tax settlement, benefit recognized in period						0.7
Range of possible additional property tax obligation, minimum								10.4
Range of possible additional tax obligation, maximum			0.3					15.0
Accrual for potential property tax obligation								$ 15.0